Heart stimulation electrode with a conical positioning parachute

ABSTRACT

A FLEXIBLE ELECTRODE IS PROVIDED WITH A CONICAL PARACHUTE WHICH PERMITS THE BLOOD FLOWING IN A VEIN TO DRAW THE ELECTRODE INTO THE HEART SO THAT THE ELECTRODE MAY BE USED IN CONNECTION WITH AN EXTERNAL POWER SOURCE FOR STIMULATING THE HEART. A LIGHT PULL ON THE LEAD INVERTS THE PARACHUTE FOR WITHDRAWAL WITHOUT DAMAGE TO THE VEIN TISSUE.   D R A W I N G

March 6, 1973 R. E. AVERY 3,719,190

HEART STIMULATION ELECTRODE WITH A CONICAL POSITIONING PARACHUTE Filed March 9, 1971 INVEN'TOR.

ROGER E. AVERY BY ,mm/ M/{g ATTORNEY United States Patent 3,719,190 HEART STIMULATION ELECTRODE WITH A CONICAL POSITIONING PARACHUTE Roger E. Avery, Melville, N.Y., assignor to Avery Laboratories, Inc., Farmingdale, N.Y. Filed Mar. 9, 1971, Ser. No. 122,457 Int. Cl. A61m J/04 U.S. Cl. 128-418 5 Claims ABSTRACT OF THE DISCLOSURE This invention relates to electrodes and in particular to electrodes suited for insertion through a peripheral vein to make electrical contact with the heart for purposes of electrical stimulation from an external source of electrical energy.

BACKGROUND OF THE INVENTION Patients sulfering from an acute heart attack often require the application of electrical stimulus in order to keep the heart operating during a recuperation period. In order to apply the stimulus it is necessary to connect electrodes to the heart with electrical conductors leading from the electrodes to a source of electrical energy. Frequently patients require the use of a defibrillator under conditions where a delay of a few moments in applying the electrodes may spell the difference between life and death. Under such conditions, the electrodes of this invention may be inserted through any of the peripheral veins in the legs, arm, neck and can be inserted through a needle or through a cutdown in the skin. Prior art electrodes were manually pushed up into the vein and followed by means of a fiuoroscope. When the physician observed the electrode tips reaching the ventricle chamber of the heart, he either wedged the electrode into the base of the right ventricle called the apex, or he let it flow into the outflow tract. When it reached the desired point, he taped the other end of the electrode onto the patients arm. In about ten days an electrode inserted in this manner becomes entrapped in growing tissue. In many instances, it is desirable to remove the electrode before it becomes ingrown.

The present invention provides a flexible electrode assembly which may be inserted into the vein and which carries a parachute which draws the electrode directly into the heart cavities as it is swept along by the flow of blood. The parachute is made of a flexible material and is so constructed that a light pull Will invert the parachute to permit it to be withdrawn with the electrode through the veins without damage to the tissues.

According, it is an object of this invention to provide an electrode assembly that can be drawn into the heart cavity by force of the blood stream.

A particular object of this invention is to provide an improved heart electrode assembly.

Another object is to provide a heart electrode assembly which may be readily withdrawn.

Still another object of this invention is to provide a heart electrode having a parachute for drawing the electrode through a vein.

These and other features, objects and advantages of the invention will, in part, be pointed out with particuice larity and will, in part, become obvious from the followmg more detailed description of the invention, taken in conjunction with the accompanying drawing, which forms an. integral part thereof.

In the drawings:

In the various figures of the drawing like reference characters designate like parts.

FIG. 1 is a front elevational view of an electrode;

FIG. 2 is a side elevational view taken along line 2-2 of FIG. 1; and

FIG. 3 is a side elevational view showing the electrode assembly with the parachute in an inverted position.

Referring now to FIGS. 1 and 2, where there is shown an electrode contact member generally formed of physiologically inert metal, such as platinum and which constitutes a cap member 11 secured to a flexible wire lead made of fine filaments of, say, stainless steel, or platinum wire. The electrode leads are connected to a conventional signal source such as a Pacemaker. The lead 12 is covered by an insulating material such as Teflon 14. The area 15 between the electrode portion 11 and the protective shield 14 is a bare metal cable coated with a silicone rubber primer. Suitable primers are commercially available from suppliers of silicone rubber materials. A silicone rubber parachute member 16 bridges the gap and includes a sleeve portion 17 which is sealed to the cable by the rubber primer. The parachute is frictionally secured by shrink fitting it to electrode cap member 11 and cable portion 15. A sleeve member 19 shrink fits and frictionally engages sleeve member 14. It will be appreciated that, in addition to the adhesive bond, the parachute is mechanically interlocked between electrode and sheath 14.

The physician, in order to insert the electrode into the heart, can slip this very fine assembly whose typical maximum dimension is only about 2.7 mm. into any convenient vein and then depend on the flow of liquid engaging the conical parachute 20 to float the fine assembly directly into the main vein and across to the right ventricle and then into the pulmonary outflow tract in contact with the inner wall of the heart. By making the parachute assembly of a soft resilient material and of invertible construction, the electrode can be readily withdrawn by applying a moderate pull in which case the conical portion 20 inverts to the position 20', as shown in FIG. 3, presenting a tapered face in the direction of withdrawal when the electrode assembly is withdrawn. Since the material is soft the cone is actually crimped down to a small bundle which easily passes through the conventional cannula of but 1.5 mm. ID. The chuite material should be physiologically inert and sterilizable. Silicone rubber is well suited for this purpose and is currently the preferred material.

There has been disclosed heretofore the best embodiment of the invention presently contemplated. However, it is to be understood that various changes and modifications may be made by those skilled in the art without departing from the spirit of the invention.

What I claim as new and desire to secure by Letters Patent is:

1. An electrode assembly comprising:

(a) a flexible electrical conductor;

(b) an electrically conductive electrode member fixed to one end of said conductor in electrical and mechanical connection; and

(c) a hollow cone member carried by said conductor proximate said electrode with the apex of the cone directed to the tip of the electrode.

2. The electrode assembly of claim 1 wherein said hollow cone member is formed of an elastomeric material.

3. The assembly of claim 2 wherein said elastomeric References Cited material is silicone rubber.

4. The electrode assembly of claim 1 wherein said UNITED STATES PATENTS hollow cone member is flexible at least proximate the apex 724,913 4/ 1903 Montgomery 128 245 of the cone whereby upon the application of a force in 5 2, 60,175 11 1953 Thrasher et 1 v 7, ;404 the direction from apex to base of said cone, said cone 3,437,091 4/1969 je h l i 1; 1, 112s-404 member is inverted. 3,563,245 2/1971 McLean et al 128-419 P 5. The electrode assembly of claim 1 including an ins-ulator covering the said conductor to a point proximate said electrode and said cone member having a tubular 10 portion extending from the apex of said cone constricted about a portion of said electrode and a portion of said 128 419 D 419 P conductor.

WILLIAM E. KAMM, Primary Examiner 

